Component removal from a gas stream

Abstract

In a first aspect, the disclosure provides a method for removing a component from a gas stream. A carrier gas stream is cooled by direct contact with a dehydrating solution stream. The dehydrating solution stream removes a portion of water present in the carrier gas stream and produces a dry gas stream and a wet solution stream. A portion of the component is removed from the dry gas stream by direct contact with a cold contact liquid stream. A depleted gas stream and a slurry stream are produced. Removing the portion of the component may include desublimating, freezing, condensing, depositing, or a combination thereof of the portion of the component out of the dry gas stream as a solid product. The slurry stream may include the solid product and a contact liquid. The solid product is separated from the contact liquid, producing a substantially pure solid product stream and the cold contact liquid stream.

What is claimed is: 
     
       1. A method for removing a component from a gas stream comprising:
 cooling a carrier gas stream by direct contact with a dehydrating solution stream, the dehydrating solution stream removing a portion of water present in the carrier gas stream and producing a dry gas stream and a wet solution stream; 
 removing a portion of the component from the dry gas stream by desublimating, freezing, condensing, depositing, or a combination thereof through direct contact with a cold contact liquid stream, producing a depleted gas stream and a slurry stream, wherein the portion of the component is removed as a solid product, and wherein the slurry stream comprises the solid product and a contact liquid; 
 separating the solid product from the contact liquid, producing a solid product stream and a contact liquid stream; 
 melting the solid product stream by indirect contact with an overhead stream, producing a first liquid product stream and a warm liquid stream and warming the first liquid product stream across a recuperative heat exchanger, producing a distillation feed stream; 
 cooling the slurry stream and a first recycle stream by indirect contact with a first refrigerant in a contact liquid cooler; and 
 separating the distillation feed stream into the overhead stream and a bottoms stream in a distillation column, cooling a first portion of the bottoms stream, recycling the first portion of the bottoms stream to the distillation column, and cooling a second portion of the bottoms stream in a bottoms cooler, producing a cold bottoms stream. 
 
     
     
       2. The method of  claim 1 , further comprising cooling the cold bottoms stream across the recuperative heat exchanger, producing the first recycle stream. 
     
     
       3. The method of  claim 2 , further comprising separating the warm liquid stream into a vapor stream and a second liquid product stream in a gas-liquid separator. 
     
     
       4. The method of  claim 3 , further comprising condensing the vapor stream into a third liquid product stream. 
     
     
       5. The method of  claim 4 , further comprising cooling the third liquid product stream across the recuperative heat exchanger, producing a cooled third liquid product stream. 
     
     
       6. The method of  claim 5 , further comprising passing a first portion of the second liquid product stream to the distillation column and warming a second portion of the second liquid product stream with the cooled third liquid product stream across the recuperative heat exchanger, producing a final product stream. 
     
     
       7. The method of  claim 6 , further comprising cooling a portion of the wet solution stream across the recuperative heat exchanger, producing a cold solution stream, and combining the cold solution stream with a dehydrator pre-feed stream, producing the dehydrating solution stream. 
     
     
       8. The method of  claim 7 , further comprising cooling a warm refrigerant to produce the first refrigerant using a first reverse Rankine refrigeration cycle, cooling the recuperative heat exchanger using a second reverse Rankine refrigeration cycle, or a combination thereof. 
     
     
       9. The method of  claim 1 , wherein cooling the carrier gas stream by direct contact with the dehydrating solution stream uses a direct-contact dehydrating exchanger, removing the at least the portion of the component uses a direct-contact desublimating exchanger, separating the solid product from the contact liquid uses a solid-liquid separator, or a combination thereof. 
     
     
       10. The method of  claim 1 , further comprising cooling the dry gas stream by indirect contact with the depleted gas stream using a recuperative indirect-contact heat exchanger. 
     
     
       11. The method of  claim 1 , wherein the carrier gas stream comprises flue gas, syngas, producer gas, natural gas, steam reforming gas, hydrocarbons, light gases, refinery off-gases, organic solvents, steam, ammonia, or a combination thereof. 
     
     
       12. The method of  claim 1 , wherein the component comprises nitrogen oxide, sulfur dioxide, nitrogen dioxide, sulfur trioxide, hydrogen sulfide, hydrogen cyanide, water, mercury, hydrocarbons, pharmaceuticals, ammonia, or a combination thereof. 
     
     
       13. The method of  claim 1 , wherein the contact liquid comprises water, hydrocarbons, liquid ammonia, liquid carbon dioxide, cryogenic liquids, or a combination thereof. 
     
     
       14. The method of  claim 1 , wherein the contact liquid stream may be a mixture of a solvent and an ionic compound, the solvent comprising water, hydrocarbons, liquid ammonia, liquid carbon dioxide, cryogenic liquids, or a combination thereof, and the ionic compound comprising potassium carbonate, potassium formate, potassium acetate, calcium magnesium acetate, magnesium chloride, sodium chloride, lithium chloride, calcium chloride, or a combination thereof. 
     
     
       15. The method of  claim 1 , wherein the contact liquid stream comprises a mixture of a solvent and a soluble organic compound, the solvent comprising water, hydrocarbons, liquid ammonia, liquid carbon dioxide, cryogenic liquids, or a combination thereof, and the soluble organic compound comprising glycerol, ammonia, propylene glycol, ethylene glycol, ethanol, methanol, or a combination thereof. 
     
     
       16. The method of  claim 1 , wherein the dehydrating solution stream may be a mixture of a solvent and an ionic compound, the solvent comprising water, hydrocarbons, liquid ammonia, liquid carbon dioxide, cryogenic liquids, or a combination thereof, and the ionic compound comprising potassium carbonate, potassium formate, potassium acetate, calcium magnesium acetate, magnesium chloride, sodium chloride, lithium chloride, calcium chloride, or a combination thereof. 
     
     
       17. The method of  claim 1 , wherein the dehydrating solution stream comprises a mixture of a solvent and a soluble organic compound, the solvent comprising water, hydrocarbons, liquid ammonia, liquid carbon dioxide, cryogenic liquids, or a combination thereof, and the soluble organic compound comprising glycerol, ammonia, propylene glycol, ethylene glycol, ethanol, methanol, or a combination thereof.